1. Field of the invention
The present invention relates to a copying apparatus, and more particularly, to a copying apparatus provided with an automatic document feeder and a sorter.
2. Description of the related art
In recent years, there has been a growing demand for automatic paper handling devices in carrying out a copying operation. In order to meet the demand, various types of auxiliary devices of a copying apparatus have been developed and put to practical use. For example, one of such auxiliary devices is an automatic document feeder which automatically feeds original documents one by one to the copying apparatus, and another is a sorter which sorts and groups copy paper sheets (hereinafter referred to as copy sheet).
According to a known automatic document feeder, a unit of originals comprising one original document or more placed on an original document-placing tray is sequentially fed to an exposure position until the last one of original documents has been fed thereto, and then, discharged from the copying apparatus. When a plurality of units of originals is set on the automatic document feeder with one unit of originals piled on the other, all of the copy sheets are discharged to the same tray. It is troublesome to separate the copy sheets removed from the tray from each other for every unit of originals. In order to avoid such a troublesome sheet-separating work in carrying out the copying operations of a plurality of units of originals by such an automatic document feeder, an operator is kept waiting for a few minutes with some bins being empty as long as the copying of the preceding unit of originals is in operation with the ADF unit before the operator performs the copying of the following units of originals. Further, every time the copying of a different unit of originals is performed, the operator has to perform various operations, which causes the loss of time and labor.